The vaccine was significantly more effective … if they had not b

來源: 於 2015-12-01 14:18:31 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

The vaccine was significantly more effective … if they had not been vaccinated in the previous five years.

這句話還不能說明問題嗎？ 應該好好想想是不是要年年都打疫苗，或者應該每5年打一次？